The present application generally relates to drilling devices for drilling holes in the ground. More particularly, the present application relates to a device that may be used to clean out debris, dirt, or clay that collects inside of a drill head during the drilling process. The present application is particularly useful as a clean out device for removing clay, dirt, or debris that collects inside a drill head that may be used for drilling holes in a landfill.
Landfills are used to store the vast majority of municipal solid waste generated in the United States. In fact, there are thousands of such landfills throughout the country. Landfill gas is produced by the chemical reactions and microbes during the decomposition of the waste material. The landfill gas typically contains methane gas, which is a combustible gas. As the landfill gas increases, the pressure and quantity of landfill gas may create a dangerous condition. As a result, holes are drilled into the landfill that are used to monitor the landfill gas or vent the landfill gas where it can be flared or “burned off.” In addition, in recent years efforts have been made to harness the gas produced in the landfill and use the gas as an energy source. Therefore, there are a number of reasons why holes are required to be drilled in a landfill.
The holes are typically drilled using a mobile drill rig, such as a drill rig based on a tractor or truck. A drill head or drill bucket is used to drill and remove the landfill materials as the hole is being formed. The holes may be of various sizes. For example, holes are typically in the range of 24-48 inches in diameter, with a 36 inch diameter hole being fairly common. However, in some applications holes 6 feet or more in diameter may be required. The drill head or drill bucket is typically formed as a hollow cylinder having a plurality of cutting teeth located on a periphery of the bottom of the drill head. The drill head is rotated and the cutting teeth drill into the landfill until the generally open interior of the drill head becomes filled with the debris from the landfill. The drill head is removed from the hole and the debris within the interior of the drill head is emptied from the drill head. The process is repeated until the hole reaches a desired depth.
Drilling holes in a landfill presents a number of problems. Many different types of materials are encountered in the solid waste of a landfill. For example, plastic bags, household waste, tree branches, and rebar may be encountered. This debris may become caught within the interior of the drill head and must be removed before the drilling operation can continue. Furthermore, landfills often contain clay, which may be used as a cover barrier or to absorb leachate in the landfill. Clay poses the additional problem of “sticking” to the interior of the drill head. Thus, removal of the landfill debris and/or clay from the drill head is an important aspect of the drilling operation.
In the past, a variety of different approaches to removing the landfill debris and/or clay from the drill head have been used. For example, drill rig operators have tried to “shake” the debris and/or clay loose by raising and then lowering the drill head with an abrupt stop, or by rotating the drill head back and forth with abrupt reversals. Another approach has been to swing the drill head back and forth to try to loosen the debris and/or clay from the drill head. These approaches may not work, or may only partially work, leaving some debris and/or clay stuck within the drill head. However, even if these approaches do work, they result in undesirable wear and fatigue on the components of the drill rig. For example, the slewing ring between the operator cab and the base of the drill rig may undergo undesirable wear and tear that shortens its lifespan, or the Kelly bar typically attached to the drill head may undergo fatigue and stress that limits its useful lifespan. The cost of replacing or repairing the Kelly bar can be in the tens of thousands of dollars.
Recognizing that various manipulations of the drill rig in an attempt to loosen and remove the debris and/or clay within the drill head may not be effective and result in undesirable wear on the drill rig components, other methods of removal have been attempted. For example, a vertical bar welded to a large steel trench plate has been constructed. To clean out the drill head, the drill head is lowered onto the vertical bar so that the vertical bar is positioned within the interior of the drill head, and then the drill head is rotated in an attempt to remove the debris and/or clay from the drill head. The vertical bar contacts the debris and/or clay as the drill head is rotated and may knock loose some of the debris or clay within the drill head. However, the vertical bar can often get “hung up” on the debris and/or clay. When this happens the force of the rotating drill head (created by the over 50,000 foot/pounds of torque that may be provided by the drill rig) is transferred to the vertical bar, and in turn to the large trench plate causing the vertical bar and large trench plate to rotate together with the drill head.
Another approach has been to pound or screw a vertical bar into the landfill. However, when using this technique when the vertical bar gets “hung up” on the debris and/or clay, the force of rotating the drill head may cause the vertical bar to become loose from the ground and wobble as the vertical bar rotates together with the drill head.
Cleaning out the drill head is an important part of the process of drilling holes in a landfill. When a drill rig operator is unable to remove the debris and/or clay from the drill head, no drilling can occur, resulting in costly downtime. Therefore, there is a need to provide a method and/or device that may be used to clean out the drill head that does not require excessive manipulation of the drill rig and that does not include an apparatus that rotates together with the drill head when the clean out tool gets “hung up” in the interior of the drill head.